Anthraquinone dye and process of making same.



NITED STATES PATENT QFFICE.

ROBERT E. SCHMIDT AND ANDREAS JACOBI, OF ,ELBERFELD, GERMANY, ASSIGNORS TO THE FARBENFABRIKEN OF ELBERFELD COMPANY, OF

NEW YORK, N. Y.

ANTHRAQUINONE DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 666,702, dated January 29, 1901.

Application filedllllay 16, 1900. berial No. 16,849. (Specimens) T0 (L35 whom it may concern.-

Be it known that we, ROBERT E. SCHMIDT and ANDREAS J ACOBI, doctors of philosophy, chemists, (assignors to the FARBENFABRIKEN on ELBERFELD COMPANY, of New York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in New Anthraquinone Dyes; and we hereby declare the following to be a clear and exact description of our invention.

Our invention relates to the production of new dyestufis by causing primary aromatic amins to act on the nit-rooxyanthraquinonesulfonic acid having the following formula:

I AMA/ lee/ l This acid can be obtained by sulfouating and then nitrating erythroxyanthraquinone. The dyestuffs 11] us obtained are acids having in a free state the following general formula:

(in which formula R means an alphyl radical, such as phenyl, tolyl, Xylyl, or the like.)

The new coloring-matters represent darkblue powders more or less easily soluble in water with a blue color. They yield on unmordanted wool blue shades and on chromemordanted wool greenish-blue shades.

In carrying out our new process practically we can proceed as follows, the parts being by weight: A mixture prepared from ten parts of the potassium salt of nitrooxyanthraquinone-sulfonic acid having the above-given formula, two hundred parts of a fifty-per-cent. acetic acid and one hundred parts of paratoluidin, is heated in a water-bath for about from two to three days until the melt has assumed a dark greenish-blue color, Subsequently the reaction mixture is poured into dilute hydrochloric acid. The coloring-matter which is separated by means of this operation is filtered off and further purified in the usual way. It has in a free state the following formula:

l U v When dry and pulverized, the new coloringmatter represents a dark-blue powder diffi- -cultly soluble in water with a blue color, also soluble with difficulty in a dilute caustic alkaline solution with a bluish-green color. By concentrated sulfuric acid (of 66 Baum) it is dissolved, yielding a green solution, the color of which changes into blue on the addition of boric acid.

The new dyestnfi dyes unmordanted wool reddish-blue shades and c'hrome-mordanted wool greenish-blue shades.

The process proceeds in an analogous manner if instead of paratoluidin other aromatic amins are employed in the above example.

Having now described our invention and in what manner the same is to be performed, what we claim as new, and desire to secure by Letters Patent, is-

l. The process for producing new anthraquinone dyestuffs which process consists in first heating the nitrooxyanthraquinone-sulfonic acid having the formula on oo so n l l- \loo with primary aromatic amins, secondly separating the new dyestufis thus produced from the reaction mixture and finally isolating the same,substantially as hereinbefore described.

2. The process for producing a new anthraquinone dyestuff which process consists in first heating the nitrooxyanthraquinone-sulfonic acid having the following, formula:

l I Y quinone dyestuff having in'a free state the 50 following formula:

which is, when dry and pulverized, a darkblue powder difiicultly soluble in water with a blue color, being also soluble with difficulty in dilute caustic soda-lye with a bluish-green color, being dissolved by concentrated sulfuric acid of 66 Baum yielding a green solu- I-ion'the color of which turns into blue on the addition of boric acid, dyeing. unmordanted wool reddish-blue shades and chrome-mordanted wool greenish-blue shades, substantially as hereinbefore described.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

ROBERT E. SCHMIDT. ANDREAS JAOOBI.

Witnesses: OTTO KoNIe, F. A. RITTERHAUS. 

